The phase angle is associated with upper arm muscle circumference but not with sarcopenia in continuous ambulatory peritoneal dialysis patients

AimsLimited studies on phase angle (PhA) and sarcopenia in continuous ambulatory peritoneal dialysis (CAPD) patients. We want to explore the association between PhA and sarcopenia and clarify its significance and value in diagnosing sarcopenia. MethodsWe included 87 CAPD patients. We measured the PhA and body composition by bioelectrical impedance analysis. All patients had their handgrip strength(HGS) measured. Then, we divided patients into the sarcopenia (n=25) group and non-sarcopenia(n=62) group according to the sarcopenia diagnostic strategy formulated by the Asian Working Group for Sarcopenia. ResultsUnivariate analysis shows PhA is positively associated with HGS, skeletal muscle mass (SMM), and Upper arm muscle circumference (AMC). After adjustments for sex, age, diabetes, BMI, extracellular water ratio(E/T), extra water (OH), serum creatinine, total kt/v, and residual kt/v, PhA remains correlated to HGS and AMC, but not to SMM. In the multivariate logistic model, PhA is not correlated to sarcopenia. The AUROC of PhA for sarcopenia is 0.76(95% CI, 0.65-0.86, P <0.01, fig 3). The optimal cut-off value is identified as [&le;]5.25(sensitivity 74%, specificity 76%). O_FIG O_LINKSMALLFIG WIDTH=197 HEIGHT=200 SRC="FIGDIR/small/22277470v1_fig3.gif" ALT="Figure 3"> View larger version (22K): org.highwire.dtl.DTLVardef@176dc17org.highwire.dtl.DTLVardef@6b804corg.highwire.dtl.DTLVardef@1b401e5org.highwire.dtl.DTLVardef@e88730_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFig 3C_FLOATNO The ROC curve of PhA for sarcopenia in all of the patients, the AUCROC is 0.76(p< 0.01). C_FIG ConclusionThis study illustrates that older age and higher total kt/v are risk factors for sarcopenia. PhA is positively associated with HGS and AMC but not with sarcopenia in CAPD patients. These results suggest that PhA can predict muscle mass and strength in CAPD patients, but its diagnosis value for sarcopenia needs more studies.